Question

Energy pyramids of an ecosystem tend to diminish at higher trophic levels. This is because at each successive level

• A. the organisms become smaller
• B. energy is stored and therefore less is passed on to the next level
• C. energy is being concentrated in larger organisms
• D. energy is being lost form one level to the next

Answer 1

The correct option is D energy is being lost form one level to the next

Energy flow in an ecosystem is always unidirectional. Only 10% of the gross productivity of the producers is trapped by the herbivores' bodybuilding. Subsequently, only 10% of the herbivore productivity is utilised for raising productivity of primary consumers. The remaining 90% is consumed and burned out in ingestion, respiration, maintenance of the body heat and other activities.

Higher carnivores are similarly able to retain only 10% of the energy present in the preceding primary carnivores. This is called the 10% law. This loss in the energy is the constraint that limits the trophic levels. All food chains and webs have at least two or three trophic levels, and there could be a maximum of four to six trophic levels.